Proton Translocating ATPases: Introducing Unique Enzymes Coupling Catalysis and Proton Translocation through Mechanical Rotation

2004 ◽  
pp. 235-260 ◽  
Author(s):  
Masamitsu Futai ◽  
Ge‐Hong Sun‐Wada ◽  
Yoh Wada
Keyword(s):  
Proton Translocation ◽  
Mechanical Rotation

scholarly journals The site of attachment of retinal in bacteriorhodopsin. The epsilon-amino group in Lys-41 is not required for proton translocation.

1982 ◽  
Vol 257 (15) ◽  
pp. 8596-8599 ◽  
Author(s):  
K S Huang ◽  
M J Liao ◽  
C M Gupta ◽  
N Royal ◽  
K Biemann ◽  
...  
Keyword(s):  
Proton Translocation ◽  
Amino Group

scholarly journals Publisher's Note: “Mechanical rotation at low Reynolds number via reinforcement learning” [Phys. Fluids 33, 062007 (2021)]

2021 ◽  
Vol 33 (7) ◽  
pp. 079902
Author(s):  
Yuexin Liu ◽  
Zonghao Zou ◽  
Alan Cheng Hou Tsang ◽  
On Shun Pak ◽  
Y.-N. Young
Keyword(s):  
Reynolds Number ◽  
Reinforcement Learning ◽  
Low Reynolds Number ◽  
Low Reynolds ◽  
Mechanical Rotation

Mechanical rotation at low Reynolds number via reinforcement learning

2021 ◽  
Vol 33 (6) ◽  
pp. 062007
Author(s):  
Yuexin Liu ◽  
Zonghao Zou ◽  
Alan Chen Hou Tsang ◽  
On Shun Pak ◽  
Y.-N. Young
Keyword(s):  
Reynolds Number ◽  
Reinforcement Learning ◽  
Low Reynolds Number ◽  
Low Reynolds ◽  
Mechanical Rotation

scholarly journals Cryo-EM structure and dynamics of the green-light absorbing proteorhodopsin

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Stephan Hirschi ◽  
David Kalbermatter ◽  
Zöhre Ucurum ◽  
Thomas Lemmin ◽  
Dimitrios Fotiadis
Keyword(s):  
Proton Translocation ◽  
Functional Characterization ◽  
Green Light ◽  
Proton Donor ◽  
Molecular Organization ◽  
Primary Proton ◽  
Proton Pumps ◽  
Model Protein ◽  
Dynamics Simulations ◽  
And Function

AbstractThe green-light absorbing proteorhodopsin (GPR) is the archetype of bacterial light-driven proton pumps. Here, we present the 2.9 Å cryo-EM structure of pentameric GPR, resolving important residues of the proton translocation pathway and the oligomerization interface. Superposition with the structure of a close GPR homolog and molecular dynamics simulations reveal conformational variations, which regulate the solvent access to the intra- and extracellular half channels harbouring the primary proton donor E109 and the proposed proton release group E143. We provide a mechanism for the structural rearrangements allowing hydration of the intracellular half channel, which are triggered by changing the protonation state of E109. Functional characterization of selected mutants demonstrates the importance of the molecular organization around E109 and E143 for GPR activity. Furthermore, we present evidence that helices involved in the stabilization of the protomer interfaces serve as scaffolds for facilitating the motion of the other helices. Combined with the more constrained dynamics of the pentamer compared to the monomer, these observations illustrate the previously demonstrated functional significance of GPR oligomerization. Overall, this work provides molecular insights into the structure, dynamics and function of the proteorhodopsin family that will benefit the large scientific community employing GPR as a model protein.

scholarly journals A redirected proton pathway in the bacteriorhodopsin mutant Tyr-57–>Asp. Evidence for proton translocation without Schiff base deprotonation.

1994 ◽  
Vol 269 (46) ◽  
pp. 28851-28858
Author(s):  
S Sonar ◽  
T Marti ◽  
P Rath ◽  
W Fischer ◽  
M Coleman ◽  
...  
Keyword(s):  
Schiff Base ◽  
Proton Translocation

scholarly journals The Texture of a Slate From Nantlle, Caernarvon, North Wales

Texture ◽  
1972 ◽  
Vol 1 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Gerhard Oertel ◽  
Prem P. Phakey
Keyword(s):  
Ultrathin Section ◽  
Orthorhombic Symmetry ◽  
X Ray ◽  
Plane Normal ◽  
North Wales ◽  
Pole Figures ◽  
Sheet Silicate ◽  
Diffraction Patterns ◽  
Local Dissolution ◽  
Mechanical Rotation

A specimen of Cambrian slate from the slate belt in North Wales has been thinned by the ion bombardment technique to produce an ultrathin section with the specimen plane normal to the cleavage plane. This specimen has been investigated with the electron microscope by electron transmission. Selected area diffraction patterns allow identification of individual sheet silicate grains. The pole figures of the basal planes of two sheet silicate minerals, muscovite and chlorite, have been measured with an X-ray pole-figure goniometer and both show an elongated maximum normal to the slaty cleavage, with orthorhombic symmetry. While the preferred orientation could be the result of mechanical rotation of rigid flakes in a deforming matrix, the texture (the overall pattern due to the shapes and sizes of grains and their angular relations to each other) can only be explained if considerable recrystallization is assumed. It is tentatively proposed that local dissolution at points of stress-concentration with simultaneous redeposition of the dissolved material in less stressed regions may have allowed closely packed grains to act as if they were mechanically rotating rigid flakes, yet to accommodate their shapes enough to prevent interlocking.

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